Many vehicles today are equipped with a passive entry system, or “PES.” In some PES implementations, a key fob communicates with a computer of the motor vehicle, and the motor vehicle computer operates to automatically unlock one or more door locks of the motor vehicle in response to detection of the key fob being in close proximity to the motor vehicle. This allows an operator of the vehicle to approach the vehicle and open the door without having to manually unlock the door with a key or to manually press a button on the key fob. In some such applications, the motor vehicle computer is also configured to automatically lock the vehicle in response to detection of the key fob being outside of the close proximity of the motor vehicle.
Another known type of hands-free vehicle access or entry system employs an infrared (“IR”) detector assembly. Typically, such systems may use an active near infrared arrangement including multiple IR LEDs and one or more sensors in communication with a computer or other circuitry. The computer is typically operable in such an assembly to calculate the distance of an object from the assembly by timing the interval between emission of IR radiation and reception by the sensor(s) of at least a portion of the emitted IR radiation that is reflected by the object back to the sensor(s), and then interpreting the timing information to determine movement of the object within the IR field. Exemplary IR movement recognition systems are disclosed in US Patent Application Publication 20120200486, US Patent Application Publication 20150069249, and US Patent Application Publication 20120312956, and US Patent Application Publication 20150248796, the disclosures of which are incorporated herein by reference in their entireties.